Three Dimensional Structure of Microridges of the oral mucosal epithelium

用扫描电镜和透射电镜观察了鲤鱼口腔黏膜上皮的表层细胞和上皮细胞的细胞骨架。微脊在上皮表面形成。上皮细胞包含两种类型的囊泡：粘液分泌囊泡和包被囊泡。大多数粘液囊位于细胞中心靠近高尔基体的位置。在冻裂复制体中，膜内颗粒在分泌囊泡的膜中丰富，但在顶质膜中很少。被包被的囊泡位于顶端和基部细胞质中。大量粗大的纤维被认为是角蛋白纤维，它们在细胞中随机分布，形成网状结构。在中央细胞质中稀疏的粗丝与分泌囊泡和其他膜细胞器的膜相连。一层紧密排列的细丝，被认为是肌动蛋白细丝，在顶质膜下面。微管也出现在顶端细胞质中，几乎与细胞表面平行。这两种囊泡都与细丝和粗丝相连。

Superficial cells of the fish oral mucosal epithelium in the carp and cytoskeleton of the epithelial cells are examined by scanning and transmission electron microscopy. Microridges are formed on the surface of the epithelium. Epithelial cells contain two types vesicles : mucous secretory vesicles and coated vesicles. Most of the mucous vesicles are situated in the center of the cell near the Golgi apparatus. In freeze-fracture replicas, intramembranous particles are abundant in the membranes of the secretory vesicles but rare in the apical plasma membrane. Coated vesicles are situated in the apical and subapical cytoplasm. A great number of thick filaments, considered to be keratin filaments, run randomly throughout the cell to form a meshwork. Thick filaments, which are sparse in the central cytoplasm, are connected to the membranes of the secretory vesicles and other membranous organelles. A layr of closely packed thin filaments, considered to be actin filaments, is found just beneath the apical plasma membrane. Microtubules also occur in the apical cytoplasm and run almost parallel to the cell surface. Both kinds of vesicles are connected to thin and thick filaments.